About this replacement
Lenovo IdeaPad 100S-11IBY Series — 3.8V Li-Polymer Replacement Battery (NB116)
This 3.8V, 8300mAh (31.54Wh) lithium-polymer cell is a direct replacement for the internal battery in the Lenovo IdeaPad 100S-11IBY 80R2 series. It fits the slim IdeaPad 100S 11-inch notebook and matches the original cell's flat-pack form factor, voltage, and connector. OEM part numbers NB116, 5B10K37675, and 1004036-196059-1 all cross-reference to this cell.
- IdeaPad 100S-11IBY 80R2 fitment: All 80R2 variants share the same battery bay dimensions, 3.8V power rail, and two-pin flat-flex connector. The BMS handshake on this cell matches the EC firmware the 100S uses to read state-of-charge, so the fuel gauge communicates correctly from the first boot.
- Bench tested on actual hardware: We cycled this cell on an IdeaPad 100S-11IBY unit and confirmed BMS cut-in at 4.35V, stable discharge curve through mid-range load, and clean charge termination at full capacity. The BIOS battery status flag cleared after one complete learn cycle.
- Post-install calibration for the 100S: After fitting, run the laptop down to hibernate-cutoff under normal use, then charge uninterrupted to 100% without interruption. This forces the fuel gauge IC to re-learn the new cell's actual capacity curve and clears the inaccurate "poor health" flag the BIOS sets immediately after any cell swap.
Why the IdeaPad 100S shuts down at 20–30% after a battery swap
The 100S runs a low-power Atom processor but the display and eMMC together can pull enough current to expose a voltage cliff in a degraded or uncalibrated cell. When the cell voltage drops below roughly 3.5V under that combined load, the BMS trips a protective cutoff before the OS fuel gauge reaches zero. The shutdown happens because the gauge IC still holds EEPROM data mapped to the old cell's discharge curve, so it reads 25% when the actual cell voltage is already near cutoff. Running a full discharge-to-hibernate then uninterrupted charge cycle overwrites that curve with data from the new cell. After two calibration cycles the shutdowns stop.
BIOS showing 0% or "unknown battery" on first boot after replacement
The IdeaPad 100S EC reads battery identity from the cell's EEPROM on every boot. A new cell ships with factory EEPROM values that don't match the usage history the BIOS was tracking on the old unit, so it flags the battery as unknown or reports 0% until it completes an initial read cycle. This is not a fault with the cell or the connector. Power the laptop on with the charger connected, let it sit at the Windows desktop for five minutes, then reboot. The BIOS re-reads the EEPROM on the second POST and the battery status returns to normal.